1.Field of the Invention
The present invention relates to a ventilation system incorporated in a toilet to remove offensive odors during use to be dispensed directly to the sewer line.
2. Description of the Prior Art
Modern day bathrooms often incorporate high volume exhaust fans connected either in parallel with the light switch or connected with a separate exhaust fan operating switch for actuation thereof to remove offensive odors during use of the toilet. The shortcomings of such exhaust systems has long been recognized. By their very nature, bathrooms typically fill with offensive odors during use. Such odors are only partially withdrawn therefrom during any reasonable period of exhaust fan operation. Thus, when the bathroom door is opened or another user subsequently enters, offensive odors often remain thus leaving a socially embarrassing situation. Recognition of these shortcomings in conventional exhaust systems has led to the proposal of numerous different exhaust or ventilating devices to be incorporated directly in the toilet bowl in effort to provide for direct exhaust to either the atmosphere or directly to the sewer system.
One such device proposed contemplated a serpentine construction of multiple air traps formed in conduits installed in the water storage tank and operated by means of a complicated venting and drainage system requiring flow of control air through air control valves under influence of a water jet. A device of this type is shown in U.S. Pat. No. 3,579,650 to Sloan. Such an arrangement, while satisfactory for selected situations, suffers the shortcoming that the flush water must pass through a vent tube and that the air control valves serves to choke air flow thus severely limiting the volume of exhaust air available during use.
Other efforts have led to the proposal of custom design toilet bowls with rather complicated conduit arrangements and incorporating a secondary water storage tank with control elements therein. Such devices provide for a blower to be connected to the sewer upstream of a trap valve. A device of this type is shown in U.S. Pat. No. 4,800,596 to Menge. While satisfactory for some applications, systems of this type suffer the shortcoming that the toilet bowl construction required is rather complex and expensive to manufacture and requires a storage tank having an unacceptably high profile. Furthermore, in a design of this type the water trap is not utilized as the first barrier to the sewer. The assurance of a leak-free system is wasted by having placed the blower between the sewer line and the water trap. Moreover, the control systems utilized in this type are dependent on the availability of water pressure in the water main thus rendering such devices inoperable when water pressure is low or non-existent.
Other efforts to provide a satisfactory exhaust system have led to the proposal of another custom styled toilet bowl construction, mounting a water storage tank requiring a pneumatic seal for proper operation and which vents exhaust gases to the atmosphere. A device of this type is shown in U.S Pat. No. 5,029,346 to Fernald. While providing some improvement in operation, devices of this type suffer the shortcoming that the toil bowl construction is relatively expensive to manufacture and the use of the tank's overflow tube as an exhaust conduit severely limits airflow due to its small cross-section resulting in residual offensive odors remaining even after operation.
Thus, there exists a need for a toilet bowl ventilating system which provides for a high volume of exhaust air flow during use to be introduced directly to the sewer line and which will positively close off communication with such sewer line during the flush cycle and during any remedial household measures taken to rectify plugging of the sewer line as by application of conventional household plungers to the drain from the toilet bowl.